Probing into the isomers and bonding natures of PuC₆

Isomers, bonding characters and spectra of the PuC₆ were investigated with DFT and ab initio calculations. A fan-type structure with septet spin multiplicity was found to have the lowest energy through extensive structure research. The energy orders of low-lying isomers were assessed with different DFT functionals and CCSD (T). The main ionic natures of Pu-C bonds derived from electrostatic interaction were revealed by QTAIM. Meanwhile, the quantum-exchange correlation from the directly orbital overlaps of Pu and C also play a significant role in stabilizing. IR and UV-vis spectra were simulated to provide spectra information for the structural identification of PuC₆ in future experiments.